Building structure



FIG. 1 is a front elevation view of a building structure.

FIG. 2 is a right side elevation view.

FIG. 3 is a rear elevation view.

FIG. 4 is a left side elevation view.

FIG. 5 is a top elevation view.

FIG. 6 is a bottom elevation view. 

The ornamental design for a building structure, as shown. 